#include <iostream>
#define EIGEN_USE_SYCL
#include <unsupported/Eigen/CXX11/Tensor>

using Eigen::array;
using Eigen::SyclDevice;
using Eigen::Tensor;
using Eigen::TensorMap;

int
main()
{
	using DataType = float;
	using IndexType = int64_t;
	constexpr auto DataLayout = Eigen::RowMajor;

	auto devices = Eigen::get_sycl_supported_devices();
	const auto device_selector = *devices.begin();
	Eigen::QueueInterface queueInterface(device_selector);
	auto sycl_device = Eigen::SyclDevice(&queueInterface);

	// create the tensors to be used in the operation
	IndexType sizeDim1 = 3;
	IndexType sizeDim2 = 3;
	IndexType sizeDim3 = 3;
	array<IndexType, 3> tensorRange = { { sizeDim1, sizeDim2, sizeDim3 } };

	// initialize the tensors with the data we want manipulate to
	Tensor<DataType, 3, DataLayout, IndexType> in1(tensorRange);
	Tensor<DataType, 3, DataLayout, IndexType> in2(tensorRange);
	Tensor<DataType, 3, DataLayout, IndexType> out(tensorRange);

	// set up some random data in the tensors to be multiplied
	in1 = in1.random();
	in2 = in2.random();

	// allocate memory for the tensors
	DataType* gpu_in1_data = static_cast<DataType*>(sycl_device.allocate(in1.size() * sizeof(DataType)));
	DataType* gpu_in2_data = static_cast<DataType*>(sycl_device.allocate(in2.size() * sizeof(DataType)));
	DataType* gpu_out_data = static_cast<DataType*>(sycl_device.allocate(out.size() * sizeof(DataType)));

	//
	TensorMap<Tensor<DataType, 3, DataLayout, IndexType>> gpu_in1(gpu_in1_data, tensorRange);
	TensorMap<Tensor<DataType, 3, DataLayout, IndexType>> gpu_in2(gpu_in2_data, tensorRange);
	TensorMap<Tensor<DataType, 3, DataLayout, IndexType>> gpu_out(gpu_out_data, tensorRange);

	// copy the memory to the device and do the c=a*b calculation
	sycl_device.memcpyHostToDevice(gpu_in1_data, in1.data(), (in1.size()) * sizeof(DataType));
	sycl_device.memcpyHostToDevice(gpu_in2_data, in2.data(), (in2.size()) * sizeof(DataType));
	gpu_out.device(sycl_device) = gpu_in1 * gpu_in2;
	sycl_device.memcpyDeviceToHost(out.data(), gpu_out_data, (out.size()) * sizeof(DataType));
	sycl_device.synchronize();

	// print out the results
	for (IndexType i = 0; i < sizeDim1; ++i) {
		for (IndexType j = 0; j < sizeDim2; ++j) {
			for (IndexType k = 0; k < sizeDim3; ++k) {
				std::cout << "device_out"
						  << "(" << i << ", " << j << ", " << k << ") : " << out(i, j, k) << " vs host_out"
						  << "(" << i << ", " << j << ", " << k << ") : " << in1(i, j, k) * in2(i, j, k) << "\n";
			}
		}
	}
	printf("c=a*b Done\n");
}
